The invention relates to a thermofonning method and apparatus for flat thin sheet plastic substrates having printed material thereon.
It is known in the prior art to clamp the printed substrate between a pair of clamp plates, then heat the substrate, and then thermoform same into a contoured three dimensional workpiece by pushing a tool face into the substrate far enough to allow the hot elastic plastic material to create a vacuum or pressure seal against the tooling, followed by application of vacuum or pressure to conform the plastic substrate to the shape of the tooling.
The present invention provides an improvement enabling higher throughput.